(a) Technical Field
The present invention relates to a system and method for estimating a remaining travel distance of an electric vehicle. More particularly, it relates to a method of estimating a DTE (Distance To Empty) from the amount of the present remaining fuel (the amount of remaining electricity) in an electric vehicle.
(b) Background Art
An electric vehicle can travel by driving motors using electricity charged in a battery. It is very important in an electric vehicle to check its battery state, for example, the present temperature of the battery and the SOC (State Of Charge) of the battery, and manage the battery state to be kept above a predetermined level.
A BMS (Battery Management System), involved in the maintenance of the entire state of the battery, prevents reduction of a battery life due to deterioration of durability. It also helps a vehicle to travel based on its battery states by transmitting the SOC information of the battery to a vehicle controller that controls the battery and its states.
Notably, it is important to check the battery SOC in electric vehicles using a high-voltage battery so that the driver does not end up stranded due to loss of power. Therefore, there is a need for the development of a technology for checking the remaining capacity of the battery thereby informing the driver of its status during vehicle operation.
In the case of the vehicles using common fossil fuel, such as gasoline and diesel, there are well known methods for measuring the amount of fuel remaining in a fuel tank, e.g., a liquid level sensor. The measurement from this liquid level sensor is then used to estimate the DTE based on the amount of fuel remaining in the fuel tank multiplied by an accumulated fuel efficiency.
On the other hand, a typical method of calculating the present SOC of a battery of an electric vehicle during operation is to calculate the present SOC of a battery by measuring the amount of discharged current used per a unit time.
However, estimating the DTE of an electric vehicle from the present amount of remaining capacity of a battery has not been possible at this time due to various technical problems, such as possible risks of providing incorrect information due to difficulty in estimation and presence of estimation errors. Thus, drivers could be stranded through no fault of their own due to inaccurate readings. Accordingly, there is a need for a technique for estimating the DTE of an electric vehicle that provides a greater degree of accuracy than the conventional methods.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.